<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
     .parent{
         width: 200px;
         height: 200px;
         background-color: red;
         position: relative;
     }
     /* 绝对定位的元素移动的位置，是离他最近的给了定位的父元素 */
     /* left,right,top,bottom */
     .child{
         width: 50px;height: 50px;
         background-color: salmon;
         position:absolute;
         right: 0;bottom: 0;
     }
    </style>
</head>
<body>
    <div class="parent">
         <div class="child">

         </div>
    </div>
</body>
</html>